The present invention relates to drive systems for high-inertia load devices. The invention is particularly useful with respect to motor vehicle drive systems including fly-wheels, such as described in U.S. Pat. No. 3,858,674, and is therefore described below with respect to that particular application, but it will be appreciated that the invention could advantageously be used in other applications as well, such as for driving heavy machinery whose speed must be frequently varied.
U.S. Pat. No. 3,858,674 describes a drive system including an electrical motor and flywheel particularly useful for electrical motor vehicles. Such a drive system includes a bi-directional variable speed unit coupling the flywheel, serving as a high-inertia body, to the driven electric motor vehicle, for controlling the speed thereof such that when the vehicle is accelerating, it draws energy from the flywheel, and when it is decelerating, it returns energy to the flywheel.